How to Clear Cloudy Pool Water With a Sand Filter

If your pool water looks a little cloudy, one of the ways to clean it is through your sand filter. Below, we’ll discuss how to clear a cloudy salt water pool using a sand filter, tips on filter maintenance, and more. 

What Are Sand Filters?

As apparent from its name, a pool sand filter uses sand to filter pool water. Pool water enters through an inlet pipe into the filter tank, passing through a chamber filled with sand, which traps particles, debris, leaves, and other contaminants. The clean water then exists through an outlet pipe at the bottom of the tank back into the pool. 

Why Is My Pool Water Cloudy?

Most of the time, pool clarity issues are linked to problems with filtration. If your pool water isn’t as clear as it should be, or you can spot visible debris that the filter should have removed, this can indicate that your filter isn’t working effectively.

There are two other ways to identify if there is a problem with your sand filter. 

  1. Check the pressure gauge. The PSI rating should be between ten and twenty-five. If the pressure is ten PSI higher than usual, your filter may be clogged up, causing a cloudy pool. 
  1. If the pressure is five PSI lower than usual, this means the water isn’t flowing through quickly enough. This is likely because of a blockage caused by leaves, twigs, or other debris. 

How to Clear Cloudy Pool With Sand Filter

If your filter is clogged up and causing your pool water to become cloudy, it’s time to backwash. The backwashing process is pretty straightforward, but be sure to understand what to do first to avoid damaging your filter. You will need a backwash hose, so make sure you have one ahead of time. 

Next, follow these steps to backwash your sand filter. 

  1. Turn off the filter system and remove the skimmer basket. 
  1. Attach your backwash hose to the filter waste port, also known as the waste line or backwash post. This is where a lot of water will flow out, so ensure the end is attached correctly. 
  1. Next, turn your multiport valve to the Backwash position, and turn the filter system back on. Water will start flowing out of the backwash port and through the hose. 
  1. Before running the filter, ensure your pool’s water level is at least halfway up the skimmer since you’ll be losing pool water in the process.
  1. Let the water run for about one minute or until it runs clear. Check your filter’s sight glass or the clarity of the water coming out of the backwash hose to see if it’s clean enough. 
  1. Turn your filter system off and shift the valve from ‘Backwash’ to ‘Rinse’ (or a ‘Waste’ setting if you don’t have ’Rinse’). This will help remove sand from the lines before the water starts flowing back into your pool. 
  1. Make sure your filter is off before moving the valve into a new position. Moving the valve handle with the filter on can damage the valve handle gasket. 
  1. Turn the filter system back on and rinse for about thirty seconds. 
  1. Turn it off again and turn the multiport valve to the ‘Filter’ setting. The backwashing process is now complete, and you can run the filter as usual. 
  1. Refill your pool and test and balance the pool water as necessary. The backwash process will remove water from your pool, so you’ll have to rebalance your chemicals.

You’re done! If a dirty sand filter was causing the issue, your pool water should be clear after backwashing. If the cloudy pool problem still isn’t solved, this could indicate a different issue. 

Check all your pool chemical levels to ensure the problem isn’t caused by pH imbalance. This might also be an indication that it’s time to replace your pool sand. 

If all else fails, check for any damage to your sand filter. If your sand filter is very old and cheap, you should call a professional to replace it entirely. 

Make sure not to backwash too frequently. A clean filter is good, but a slightly dirty filter with buildup actually helps capture a lot of debris. Only backwash if your filter is clogged, your pool water is cloudy, or you notice a lot of dirt, leaves, and contaminants.

Looking for more helpful pool care insights? Don’t miss our posts on how to clear cloudy pool water with Baquacil and why your pool filter is shooting out cloudy water!

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